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Tetsuya Matsumoto

Publications and source records attributed to Tetsuya Matsumoto.

At least 19 recordsLinked to original sources
PubMed2003

Protection against lethal intra-abdominal sepsis by 1-(3-dimethylaminopropyl)-3-ethylurea.

Sodium hyaluronate-carboxymethylcellulose (HA/CMC) formulations are gels that effectively reduce postoperative adhesions in both animals and humans, when placed in the peritoneal or pelvic cavities concomitant with surgical manipulation. However, it has been suggested that the use of these products may increase the risk of peritoneal infection after contamination with intestinal contents during surgery. Using the rat intra-abdominal sepsis model, we found that administration of HA/CMC gels before bacterial challenge did not increase mortality but did significantly protect rats against lethal infection. This effect was dose and time dependent. Protection was conferred not by the HA/CMC gels themselves but by 1-(3-dimethylaminopropyl)-3-ethylurea (EDU), a small molecule released from the gel complex under physiologic conditions. Our results suggest that the protective effect exhibited by EDU is related to down-regulation of T cell-dependent responses and suppression of the proinflammatory-cytokine cascade associated with mortality during the early phase of disease.

Abdominal Abscess↗
PubMed2003

Angiotensin-converting enzyme inhibition but not angiotensin II type 1 receptor antagonism augments coronary release of tissue plasminogen activator in hypertensive patients.

OBJECTIVES: We compared the effects of perindopril and losartan on endothelium-dependent coronary vasomotor and fibrinolytic function. BACKGROUND: The renin-angiotensin system regulates the vascular fibrinolytic balance. However, the effects of angiotensin-converting enzyme inhibitors and angiotensin II type 1 receptor antagonists on coronary fibrinolytic function have not been compared in hypertensive patients. METHODS: Forty-five patients with hypertension were randomly assigned to three groups: 16 patients were treated with perindopril (4 mg/day) for four weeks; 15 were treated with losartan (50 mg/day) for four weeks; and 14 were not treated with either perindopril or losartan (control group). Graded doses of bradykinin (BK) (0.2, 0.6, and 2.0 microg/min) were administered into the left coronary artery. Coronary blood flow (CBF) was evaluated by Doppler flow velocity measurement. RESULTS: Bradykinin induced dose-dependent increases in CBF in all groups. The increases in CBF induced by BK in the perindopril and losartan groups were significantly greater than those in the control group. Net coronary tissue-type plasminogen activator (t-PA) release was enhanced by BK in all groups, and the increase in the perindopril group was greater than that in the losartan and control groups. Bradykinin did not alter plasminogen activator inhibitor type 1 levels in any of the groups. CONCLUSIONS: Perindopril and losartan similarly augment BK-induced coronary vasodilation. Perindopril may have a greater potential to enhance the BK-induced coronary release of t-PA than losartan.

Aged↗
PubMed2003

[Fosfomycin].

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Animals↗
PubMed2002

High frequency of erythromycin A resistance and distribution of mefE and ermB genes in clinical isolates of Streptococcus pneumoniae in Japan.

The ermB and mefE genes are important in terms of their responsibility for macrolide resistance in Streptococcus pneumoniae. We investigated the distribution of the ermB and mefE genes in erythromycin A-resistant S. pneumoniae isolated in our hospital during the period 1995-1998. All amoxicillin-low-susceptible isolates were considered to be resistant to erythromycin A. All isolates with resistance to erythromycin A (minimum inhibitory concentrations [MICs], > or =0.5 microg/ml) possessed ermB or mefE genes. The MICs of erythromycin A for most mefE-positive isolates ranged from 0.5 to 2 microg/ml. On the other hand, approximately 85% of ermB-positive isolates demonstrated high-level resistance to erythromycin A (MICs, > or =4 microg/ml) while the others showed low-level resistance (MICs, 0.5 to 2 microg/ml). In ermB-positive isolates with low-level resistance, high-level resistant mutants were selected with a frequency of 3.1 x 10(-6)-1.8 x 10(-3) on agar containing 4-32 MIC of erythromycin A, whereas in mefE-positive isolates, no high-level resistant mutants were detected. Mutants from ermB-positive isolates with low-level resistance showed reversibility and heterogeneity. Our data indicated a wide distribution of erythromycin A-resistant isolates with mefE or ermB genes among amoxicillin-low-susceptible S. pneumoniae in Japan. In addition, it is likely that ermB-positive isolates with low-level resistance show heterogeneous high-level resistance.

Amoxicillin↗
PubMed2002

CD1d-dependent macrophage-mediated clearance of Pseudomonas aeruginosa from lung.

CD1d-restricted T cells are implicated as key players in host defense against various microbial infections. However, the mechanisms involved and the role they play, if any, at the mucosal surfaces where pathogenic infections are initiated is unknown. In a murine pneumonia model established by intranasal application of Pseudomonas aeruginosa, CD1d(-/-) mice showed markedly reduced pulmonary eradication of P. aeruginosa compared with wild-type mice; this was associated with significantly lower amounts of macrophage inflammatory protein-2 and reduced numbers of neutrophils within the bronchoalveolar lavage fluid. Corollarily, treatment of mice with alpha-galactosylceramide--a lipid that activates CD1d-restricted T cells--increased the amount of interferon-gamma; this was associated with rapid pulmonary clearance through enhanced phagocytosis of P. aeruginosa by alveolar macrophages. These results reveal a crucial role played by CD1d-restricted T cells in regulating the antimicrobial immune functions of macrophages at the lung mucosal surface.

Animals↗
PubMed2002

Macrolide-treated Pseudomonas aeruginosa induces paradoxical host responses in the lungs of mice and a high mortality rate.

OBJECTIVE: Accumulating data have demonstrated that macrolide antibiotics suppress Pseudomonas aeruginosa virulence, which may explain the efficacy of macrolides in clinical settings. We examined the virulence of macrolide-treated bacteria in vivo. METHODS: P. aeruginosa PAO-1 was grown for 24 h on agar containing sub-MIC antibiotics, and then mice were challenged intranasally with 10(7) cfu of bacteria. RESULTS AND CONCLUSIONS: The mortality rate of mice inoculated with bacteria grown in the presence of clarithromycin (10 mg/L), erythromycin (10 mg/L) or azithromycin (5 mg/L) was 80%, 80% and 100%, respectively. In contrast, none of the mice inoculated with non-treated bacteria or bacteria treated with other antibiotics died. Lung weight and protein concentration in bronchoalveolar lavage fluid (BALF) were significantly higher in the clarithromycin group between 3 and 9 h. Moreover, we detected higher levels of tumour necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) in the BALF of these mice. These data demonstrate that macrolide-treated P. aeruginosa induced paradoxically strong responses, such as elevation of TNF-alpha, NO and permeability in the lungs.

Animals↗
PubMed2002

The in vitro and in vivo antibacterial characterization of vancomycin and linezolid against vancomycin-susceptible and -resistant enterococci.

The present study was designed to compare in vitro antibacterial activities of linezolid and vancomycin against vancomycin-susceptible Enterococcus faecalis (VSEF) and vancomycin-resistant enterococci (VRE) isolated in Japan with those of quinupristin-dalfopristin, teicoplanin and minocycline, and the in vitro short time bactericidal activity and the in vivo activities of linezolid and vancomycin against vancomycin-susceptible and -resistant E. faecalis. The MIC90s of linezolid, quinupristin-dalfopristin, vancomycin, teicoplanin and minocycline for VSEF and VRE were both 2 mg/L, both 2 mg/L, 2 and >128 mg/L, 0.25 and >128 mg/L, and both 32 mg/L, respectively. The efficacy of linezolid for mice with bacteraemia caused by VSEF was similar to that of vancomycin, but the elimination ratio of viable organisms from the blood of mice treated with vancomycin was significantly higher than in linezolid-treated and untreated mice at 2 h post-administration, and those of the two groups at 4 and 6 h were significantly higher than in untreated mice. Moreover, linezolid was highly active in mice with bacteraemia caused by vancomycin-resistant E. faecalis because this drug had potent in vitro activity against the organisms. Our results indicate that linezolid is suitable for the treatment of VRE and VSEF bacteraemia, and vancomycin is suitable for VSEF bacteraemia.

Acetamides↗
PubMed2002

Role of interferon-gamma in inflammatory responses in murine respiratory infection with Legionella pneumophila.

The role of interferon (IFN)-gamma in host inflammatory responses, including inflammatory cytokine production, in experimental pneumonia with Legionella pneumophila was examined in IFN-gamma knockout (IFN-gamma-/-) mice. IFN-gamma-/- mice and wild-type BALB/cA mice were inoculated intranasally with L. pneumophila strain KC. The survival rate of IFN-gamma-/- mice was significantly lower than that of control mice. Viable bacterial counts in lungs and blood showed a rapid and continuous increase in IFN-gamma-/- mice, in contrast to a gradual decrease in the lungs and an intermittent bacteraemia in control mice. Histopathological analysis of L. pneumophila-infected lung tissues demonstrated mild pneumonia in control mice, whereas severe pneumonia was shown in IFN-gamma-/- mice. During the late stages of infection, the number of total bronchoalveolar lavage (BAL) cells was significantly higher in IFN-gamma-/- than in control mice. The concentrations of tumour necrosis factor-alpha and interleukin-1beta in sera of IFN-gamma-/- mice were significantly lower in control mice during the early stages of infection, suggesting suppressed production of inflammatory cytokines in IFN-gamma-/- mice. In contrast, during the late stages of infection, the levels of these cytokines were significantly higher in sera of IFN-gamma-/- mice than in control mice, suggesting severe and systemic infection in IFN-gamma-/- mice. The findings suggest that retardation of host immune responses, including inflammatory cytokine production caused by deficiency of IFN-gamma, might allow the bacteria to grow and cause fulminant pneumonia.

Animals↗
PubMed2002

[A case of falciparum malaria successfully treated with intravenous artesunate].

The case was a 28-year-old Japanese female who was considered to be infected with malaria in India. She manifested fever in Tokyo, Japan, and was brought to Toho University Hospital due to continuous high fever and severe thrombocytopenia. Ring forms at 11% of her RBCs and ICT Malaria P.f/P.v test was also positive for Plasmodium falciparum diagnosis. Not only the high parasitemia and delay of the diagnosis (6 days after the onset of fever), but also her DIC status required prompt and proper treatment. The diagnosis of severe malaria was strongly considered, and intravenous Artesunate (a qinghaosu derivative) was decided to be administered to the patient. After the four series of administration, mefloquine was subsequently given to prevent recrudescence. Parasite clearance time and fever clearance time were 24 hours and 108 hours, respectively. Thrombocytopenia was improved shortly after the treatment, but then anemia was once worsened with following gradual improvement. No other significant side effects were observed and no recrudescence occurred up to 8 months after her discharge. In Japan, very few cases treated with intravenous Artesunate were reported and our results showed its safe and excellent effect for a Japanese malaria patient.

Adult↗
PubMed2002

[Evaluation of Streptococcus pneumoniae-urinary antigen detection kit in patients with community acquired pneumonia].

We evaluated a new rapid urinary antigen detection kit. NOW Streptococcus pneumoniae (Binax Inc., USA) that detected S. pneumoniae antigen by immunochromatographic membrane assay, with 66 Japanese adult patients of community acquired pneumonia. Twenty-two (33.3%) patients were found to be positive with the kit and S. pneumoniae was isolated from six patients (27.3%) of these 22 patients. S. pneumoniae was not isolated from eight of the 22 patients by blood or sputum culture. Analysis of clinical laboratory data showed that the levels of C-reactive protein (CRP) in the serum were significantly higher in the urine-antigen positive group than those in the urine-antigen negative group. There were no significant difference between the two groups including renal function, urinalysis, clinical symptom, and severity of pneumonia. Our study suggests that more cases of community acquired pneumonia are caused by S. pneumoniae than conventional tests can currently confirm. Since it is not technically complex, does not require equipment, and detects within as quickly as in 15 minutes, the S. pneumoniae urinary antigen kit is useful for rapid diagnosis of community acquired pneumonia in adults.

Adult↗
PubMed2002

Coronary endothelium-dependent and independent vasomotor responses in patients with hypertrophic cardiomyopathy.

It is well known that coronary flow reserve (CFR) is decreased in patients with hypertrophic cardiomyopathy (HCM), but it is unclear whether coronary endothelial function is impaired. Coronary endothelial function and CFR in the coronary macro- and microcirculation was evaluated in 14 patients with HCM and 11 control subjects. Acetylcholine (ACh), bradykinin (BK) and papaverine were infused into the left coronary artery. Coronary cross-sectional area was determined by quantitative coronary angiography and coronary blood flow (CBF) was determined by the product of the coronary cross-sectional area and CBF velocity measured by an intracoronary Doppler guidewire. Acetylcholine at 100 microg induced diffuse coronary spasms of the left anterior descending coronary arteries in 3 of the patients with HCM. The changes in the diameter of the left anterior descending coronary artery and the increases in CBF induced by BK (0.2, 0.6, and 2.0 microg/min) did not differ between the 2 groups. CFR was lower in the HCM group than in the control group (p<0.01). Moreover, the ratio of BK-induced CBF increase to papaverine-induced CBF increase was comparable between the 2 groups. Endothelium-dependent vasodilation of the epicardial and resistance coronary arteries induced by BK was preserved despite the decreased CFR in patients with HCM.

Adult↗
PubMed2002

Hot spring bath and Legionella pneumonia: an association confirmed by genomic identification.

A 59-year-old man developed pneumonia 9 days after bathing in a hot spring spa. Bilateral shadows on his chest radiograph rapidly progressed after admission. He was successfully treated with erythromycin and rifampicin. Legionella pneumophila serogroup 6 was recovered from an intratrachial specimen and a significant elevation was observed in a paired indirect fluorescent antibody to Legionella. Persistent slight fever and chest rentogenographic shadows resolved after administering low-dose prednisolone to treat organizing pneumonia shown by transbronchial lung biopsy. The same serotype of Legionella was recovered from the water of the hot spring spa where the man had bathed. When the extracted DNA of these two strains showed identical restriction fragments by pulsed-field gel electrophoresis, we had direct evidence that hot spring spas can be a source of Legionella pneumonia.

Anti-Bacterial Agents↗
PubMed2002

Detection of coronary microvascular disease by means of cardiac scintigraphy.

A 76-year-old woman strictly defined as having cardiac syndrome X underwent cardiac scintigraphies. A reversible perfusion abnormality was identified by (201)thallium in the inferior segment of the left ventricle. (123)iodine meta-iodo-benzyl-guanigine uptake showed extremely diminished uptake in the inferior segment of the myocardium. (123)iodine labelled beta-methyl-iodophenyl pentadecanoic acid myocardial single photon emission computed tomography showed decreased uptake of the inferior segment in the early image, whereas the delayed images revealed significant fill-in of the tracer in the inferior segment of the myocardium. These findings suggest that coronary microvascular dysfunction causes regional myocardial ischemia, resulting in metabolic and sympathetic abnormality.

Aged↗
PubMed2002

[Rapid diagnosis of infectious diseases at the site of outpatient clinics].

It is important to diagnose the pathogen as quickly as possible to accelerate the start of appropriate treatment of patients with infectious diseases. Recently, rapid diagnostic tests improve the accuracy of diagnosis of the pathogen. Furthermore, it is also available to do the test with very simplified method by using portable kits. Many PCR and antigen detection techniques have been developed to improve the diagnosis of specific pathogens, such as influenza virus, Legionella, Chlamydia, Mycoplasma, Helicobacter pylori and Mycobacterium tuberculosis. Especially, urinary antigen detection kits are useful at the site of outpatient clinics.

Ambulatory Care↗
PubMed2002

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (2000). I. Susceptibility distribution].

The bacterial strains isolated from patients diagnosed as having urinary tract infections (UTIs) in 10 institutions in Japan were supplied between the period of August 2000 and July 2001. Then, the susceptibilities of them to many kinds of antimicrobial agents were investigated. The number of them were 511 strains. The breakdown of these strains was Gram-positive bacteria as 29.0% and Gram-negative bacteria as 71.0%. Susceptibilities of these bacteria to antimicrobial agents were as follows; vancomycin (VCM), ampicillin (ABPC) and imipenem (IPM) showed strong activities against Enterococcus faecalis. No increase in low-susceptible strains of E. faecalis observed against these antimicrobial agents. VCM showed a strong activity against MRSA preventing growth of all strains with 1 microgram/ml. In addition, the activity of arbekacin (ABK) was strong with the MIC90 of 2 micrograms/ml against MRSA and prevented growth of all strains with 4 micrograms/ml. ABK showed a strong activity against Staphylococcus epidermidis preventing growth of all strains with 0.5 microgram/ml. ABPC, cefotiam (CTM) and cefozopran (CZOP) also showed a relatively strong activity against S. epidermidis (MIC90: 4 to 8 micrograms/ml). Against Escherichia coli, carbapenems showed high activities: meropenem (MEPM) prevented growth of all strains within 0.125 microgram/ml; IPM prevented growth of all strains with 0.25 microgram/ml. CZOP and CTM also showed strong activities against E. coli: MIC90 of CZOP was within 0.125 microgram/ml; MIC80 and MIC90 of CTM were 0.25 and 0.5 microgram/ml, respectively. Quinolone resistant E. coli was detected at frequency of 14.0%, which was significantly higher than that in the last year. Almost all drugs showed strong activities against Klebsiella pneumoniae and Proteus mirabilis, and MEPM prevented growth of all strains within 0.125 microgram/ml. Against Pseudomonas aeruginosa, almost drugs were not so active. The MIC90 of carbapenems and gentamicin (GM) were 16 micrograms/ml and those of all other drugs were more than 32 micrograms/ml. Against Serratia marcescens, the MIC90 of IPM and GM were the lowest value being 2 micrograms/ml, and that of MEPM was 4 micrograms/ml.

4-Quinolones↗
PubMed2002

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (2000). II. Background of patients].

Five-hundred eighty eight bacterial strains isolated from 435 patients diagnosed as having urinary tract infections (UTIs) in 10 institutions in Japan were supplied between August 2000 and July 2001. Then, the clinical background of patients were investigated such as sex, age, and type of infections, infections and kind of bacteria, frequency of bacteria isolation by age and infections, bacteria and infections by timing of antibiotics administration, and bacteria and infections by surgical procedures. About the relationship between age and sex of patients and type of infections, the number of male patients aged less than 50 years was few, and complicated UTIs without indwelling catheter was the most frequent. In females, the number of patients aged less than 20 years was few. The majority of female patients aged 40 years and over had complicated UTIs while uncomplicated UTIs was most frequent in the patients being twenties. As for type of infections and kind of bacteria, Escherichia coli decreased when the infections became complicated, and pseudomonas aeruginosa increased when the infection became complicated. Enterococcus faecalis was isolated more frequently in complicated UTIs than in uncomplicated UTIs. Considering this result by age of patients, isolated frequency of E. coli was gradually decreased with aging in patients aged 20 years and over with uncomplicated UTIs or complicated UTIs without indwelling catheter. The isolated frequencies of Klebsiella spp., P. aeruginosa, and E. faecalis were high in the patients with complicated UTIs without indwelling catheter. In the patients aged 70 years and over with complicated UTIs with indwelling catheter, P. aeruginosa and E. faecalis were frequently isolated. As for type of causative organisms in UTIs before and after the administration of antibiotics, the isolation of bacteria was remarkably decreased after administration in the patients with uncomplicated UTIs and complicated UTIs without indwelling catheter. E. coli decreased after administration of antibiotics, and P. aeruginosa increased after administration in the patients with all types of infections. As for type of causative organisms in UTIs and surgical procedures, E. coli was frequently isolated in the patients without surgery in all types of infections, while P. aeruginosa was frequently isolated in the patients who underwent surgery. In uncomplicated UTIs, Proteus spp. and E. faecalis were frequently isolated in the patients with surgery. In complicated UTIs without indwelling catheter, Klebsiella spp. was frequently isolated in the patients without surgery and E. faecalis was frequently isolated in the patients with surgery. In complicated UTIs with indwelling catheter, most of organisms except P. aeruginosa and S. aureus were frequently isolated in the patients without surgery.

Adolescent↗
PubMed2002

[Comparative studies on activities on antimicrobial agents against causative organisms isolated from patients with urinary tract infections (2000). III. Secular changes in susceptibility].

The bacteria (Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Klebsiella spp. and Pseudomonas aeruginosa) isolated from patients diagnosed as having urinary tract infections (UTIs) in 10 institutions in Japan were supplied between August 2000 and July 2001. Then, the susceptibilities of these bacteria to various antimicrobial agents were examined, and the results were compared with those obtained between 1992 and 1999. Comparison was made by classifying strains isolated from patients into those in uncomplicated UTIs and those in complicated UTIs (including with or without indwelling catheter). E. faecalis showed good susceptibility to ampicillin (ABPC) and imipenem (IPM), and the MIC90s were 2 micrograms/ml. Also, E. faecalis showed good susceptibility to vancomycin (VCM). However, the MIC90, which was 2 micrograms/ml between 1992 and 1999, rose to 4 micrograms/ml in patients with complicated UTIs because the strains inhibited at 4 micrograms/ml increased more than before. The low susceptibility of S. aureus to arbekacin (ABK) in complicated UTIs, as shown in 1998 and 1999, recovered in 2000, and no strains inhibited at > or = 4 micrograms/ml were detected. E. coli showed good susceptibility to CTM (MIC90: 0.25-0.5 microgram/ml) and CZOP (MIC90: < or = 0.125 microgram/ml) and was not resistant to those. E. coli also showed good susceptibility to the other drugs except to penicillins. Decreases in susceptibility of E. coli to quinolones, ciprofloxacin (CPFX), and sparfloxacin (SPFX) were observed in the patients with complicated UTIs. The susceptibility of Klebsiella spp. to all drugs did not significantly change in 2000 and was generally good except to penicillins. Although the susceptibility of P. aeruginosa to carbapenems was notable, the MIC90 went up from 4 micrograms/ml to 16 micrograms/ml in complicated UTIs compared with those observed in the previous year.

Anti-Infective Agents, Urinary↗